Effect of post-weld heat treatment on inhomogeneity of aluminum/copper rotary friction welded joint

Approaches to improving thermal performance of inductors with a view to improving power density

For the new ISCAD Drive System investigations are made on a plug-in connector between the machine, where the bars are made from aluminum and the power electronic, which is mainly made from copper. Based on driving cycles and previous measurements the power dissipation and temperatures are calculated analytically. Three different plug-in connectors are examined with varied surface treatment to identify any trends on lifetime estimation, whereby the Arrhenius model is applied. Obviously the results show a higher ohmic resistance of the joint and an insufficient lifetime of the untreated connector due to the oxidation process of aluminum in air.

Lifetime estimation of a novel high current low resistance single phase plug-in connector for the ISCAD application

The joining of copper to aluminum is inevitable for certain application in the electrical industry due to good conductivity and response offered by copper, aluminum for weight reduction. Whilst in the majority of cases, aluminum and copper can be joined by adhesive bonding, mechanical fastening, fusion welding and solid-phase welding techniques. Friction welding is well known for its ability to weld aluminum to many metals and consequently is being considered seriously. The present study describes about producing a sound joint between two dissimilar metals of pre-strained aluminum to commercially pure copper. Commercial pure aluminum is strained to reduce the disparity in strength level and the effect of pre-strain on friction welding is envisaged. The stronger metal (copper) in this combination is further weakened by intentionally removing some of the material so that a sound joint is obtained. Friction welding was carried out with pre-determined process parameters and the effect of initial geometry on friction welding is illustrated. Post weld characterization such as mechanical and microstructural studies of these welds was carried out to assess the quality of welds.

V. Manjubhargavi

Papers

Influence of Rubbing Profile on Friction Welding of Pre-Strained Aluminum to Copper